380BB - INSTRUMENTATION FOR FUNDAMENTAL INTERACTIONS PHYSICS

Davide Vaccaro 
SRON Netherlands Institute for Space Research

Abstract: Transition-edge sensors (TES) have emerged as a leading technology for precision measurements in astrophysical and cosmological research, owing to their exceptional sensitivity and versatility as micro-calorimeters and bolometers. This seminar will explore the fundamental physics behind TES operation, focusing on their role as highly sensitive detectors that can measure minimal changes in incoming energy or optical power with great accuracy. We will discuss their application in major space missions, such as the Athena X-ray Integral Field Unit (X-IFU) and the LiteBIRD mission, which aim to explore the Hot and Energetic Universe and the Cosmic Microwave Background, respectively. Key to the success of these missions is the ability to read out large arrays of TES devices with high fidelity, which requires advanced multiplexing techniques allowing to read out the signals from several detectors through a single transmission line. Several multiplexing schemes have been demonstrated, the most mature being NIST's time-division multiplexing (TDM), which provides high-resolution timing for each individual detector, and SRON's frequency-domain multiplexing (FDM), which allows for the efficient readout of large TES arrays by encoding signals at different MHz frequencies. These techniques enable the scaling of TES-based detector systems for future astrophysical missions, offering a path forward for the next generation of ultra-sensitive instruments in space science.